Long-term multimodality imaging follow-up of ST-segment elevation myocardial infarction patients treated with bioresorbable vascular scaffold: advantages and challenges

BACKGROUND

Multislice computed tomography (MSCT) offers a non-invasive method of imaging bioresorbable scaffolds (BRS).

OBJECTIVES

To investigate the advantages and challenges using MSCT in the follow-up after BRS implantation.

METHOD

The BRS cohort consisting of 31 patients in the 'BRS in STEMI' trial was examined by multimodality imaging and followed long-term. Minimum lumen area (MLA) and average lumen area (ALA) were examined 12 and 36 months after BRS implantation with MSCT. Optical coherence tomography (OCT) at 12 months was used as a reference.

RESULTS

Measured by MSCT, the mean MLA was 0.05 ± 1.32 mm² ( P  = 0.85), but ALA was 1.32 (±2.59 mm², P  = 0.015) greater than by OCT. ALA and MLA did not change significantly from 12 to 36 months. MSCT identified all cases of restenosis but missed one patient with massive malapposition.

CONCLUSION

Our data support using MSCT in the follow-up after BRS implantation. Invasive investigation should still be considered for patients with unexplained symptoms.

The many roles of urgent catheter interventions: from myocardial infarction to acute stroke and pulmonary embolism

INTRODUCTION

Cardiovascular diseases (CVDs) are the leading cause of cardiovascular mortality and a major contributor to disability worldwide. The prevalence of CVDs is continuously increasing, and from 1990 to 2019, it has doubled. Global cardiovascular mortality has increased from 12.1 million in 1990 to 18.6 million cases in 2019. The development of therapeutic options for these diseases is at the forefront of interest concerning the extensive socio-economic consequences. Modern endovascular transcatheter therapeutic options contribute to the reduction of cardiovascular morbidity and mortality.

AREAS COVERED

The article concentrates on the triad of the most common causes of acute cardiovascular mortality and morbidity - myocardial infarction, ischemic stroke, and pulmonary embolism. Current evidence-based indications, specific interventional techniques, and remaining unsolved issues are reviewed and compared. A personal perspective on the possible implications for the future is provided.

EXPERT OPINION

Primary angioplasty for ST-segment elevation myocardial infarction is a well-established therapeutic option with proven mortality benefits. We suppose that catheter-based interventions for acute stroke will spread quickly from centers of excellence to routine clinical practice. We believe that ongoing research will provide a basis for the expansion of interventional treatment of pulmonary embolism soon.

Current perspectives on bioresorbable scaffolds in coronary intervention and other fields

Introduction: The first-generation bioresorbable scaffolds (BRSs) had a large strut profile to compensate for the insufficient radial strength of bioresorbable polymer materials, resulting in higher scaffold thrombosis rates than conventional drug-eluting stents. To improve the clinical safety and efficacy, the new generation BRSs have been improved by optimal structure design, post-processing of bioresorbable polymer materials, or altering bioresorbable metallic alloys.Areas covered: This review summarizes the lessons learned from the first-generation BRS, updates the clinical outcomes of trials evaluating ABSORB bioresorbable vascular scaffold at long-term and bioresorbable metallic alloy-based devices, and examines recent outcomes of BRS treated in STEMI patients. This review also provides an overview of the current clinical data of seven BRSs manufactured in Asia, and of the BRSs extended application in other clinical arenas.Expert opinion: Drawbacks of the first-generation BRSs need to be addressed by the next generation of these stents with novel materials and technologies. Clinical research, including randomized controlled trials, are required to further evaluate BRSs application in coronary artery disease. The encouraging results of BRSs innovation applied in the peripheral arteries and gastrointestinal tracts support other potential clinical applications of BRS technology.

Comparison of the everolimus-eluting bioresorbable vascular scaffold versus the everolimus-eluting metallic stent in real-world patients with ST-segment elevation myocardial infarction

INTRODUCTION

Despite the withdrawal of the ABSORB bioresorbable vascular scaffold (BVS) from clinical use, continuous observation of BVS-treated patients is necessary. In the vast majority of clinical trials, patients with ST-segment elevation myocardial infarction (STEMI) were excluded from the analysis.

AIM

To compare the early and long-term outcomes of the BVS with the everolimus-eluting metallic stent (EES) in patients with STEMI.

MATERIAL AND METHODS

Consecutive patients treated with BVS or EES in our center were screened. For analysis, only patients with STEMI were enrolled. The primary endpoint was a comparison of the target lesion failure at 12 and 24 months. The secondary endpoints encompass occurrence of the patient-oriented cardiovascular endpoint (PoCE), stent thrombosis (ST), device, and procedural success.

RESULTS

Between 2012 and 2016, 2,137 patients were hospitalized for STEMI. Of these, 123 patients received the BVS (163 scaffolds; 151 lesions), whereas in 141 patients the EES (203 stents; 176 lesions) was implanted. The median follow-up was 931 ±514 days. The primary endpoint at 12 months occurred in 9.7% in the BVS group and in 8.5% in the EES group (hazard ratio (HR) = 2.61; 95% confidence interval (CI): 0.90-7.56; p = 0.076). At 24 months the incidence of the primary endpoint was 15.2% in the BVS group and 14.9% in the EES group (HR = 2.46; 95% CI: 0.85-7.07; p = 0.095). The rates of PoCE, ST, device, and procedural success were also comparable in both groups.

CONCLUSIONS

STEMI patients treated with the BVS showed statistically similar rates of primary and secondary endpoints compared with the EES.

Predictors of bioresorbable scaffold failure in STEMI patients at 3 years follow-up

BACKGROUND

Little data are available on the long-term outcomes of bioresorbable scaffold (BRS) in the setting of ST-segment elevation myocardial infarction (STEMI). The aim of this study is to investigate three-years outcomes and predictors of BRS failure in patients presenting with STEMI.

METHODS AND RESULTS

Two prospective, single-arm registries were pooled. Incidence and predictors of clinical outcome were assessed with Kaplan-Meier and Cox regression analyses. From May-2012 to January-2015, 183 STEMI patients (58 ± 13 years, 77% males, 29% diabetics) who received a total of 256 BRS (1.4 ± 0.8 per patient) were included. 248 patients (65 ± 11 years, 74% males, 27% diabetics) treated for stable coronary artery disease (SCAD) served as control. 3-years follow-up was available in 386 (90%) patients. Device-oriented composite endpoint and scaffold thrombosis (ScT) rates were similar in the two groups (STEMI: 11.5% vs SCAD: 12.9%, P = 0.84; STEMI: 3.6% vs SCAD: 3.3%, P = 0.90). While early ScT was more frequent in SCAD patients, late/very late ScT was a feature of STEMI. While in STEMI patients the incidence of ScT was higher in vessels with RVD > 3.5 mm, a RVD < 2.5 mm was a predictor of events in stable patients. Similarly, BRS undersizing predicted events in STEMI patients, while oversizing was a predictor in stable ones. Finally, the incidence of ScT was reduced in both STEMI and stable patients (from 6.3% to 0% and from 5.80% to 0.9%) when an optimized implantation technique was used.

CONCLUSIONS

The incidence of events for three years follow-up was similar in STEMI and SCAD patients, although different timing and features underlie ScT in the two groups.

Twelve-month outcomes after bioresorbable vascular scaffold implantation in patients with acute coronary syndromes. Data from the European Multicenter GHOST-EU Extended Registry

AIMS

The aim of this study was to report on the midterm outcomes of patients undergoing percutaneous coronary intervention with bioresorbable vascular scaffolds (BVS) for the treatment of acute coronary syndromes (ACS) and compare with those of patients with stable coronary artery disease (sCAD).

METHODS AND RESULTS

One thousand four hundred and seventy-seven (1,477) patients underwent implantation of one or more BVS (Absorb BVS; Abbott Vascular, Santa Clara, CA, USA) at 11 European centres and were included in the GHOST-EU registry. Admissions comprised 47.1% of the patients (951 BVS) with ACS, and 52.8% (1,274 BVS) with sCAD. During a median follow-up of 384 (359-460) days, patient-oriented endpoints (PoCE), including all-cause death, any infarction, any revascularisation, were recorded in 271 patients (12-month incidence in ACS patients: 18.5% vs. 11.6% in the sCAD group, p<0.001). Device-oriented composite endpoints (DoCE), cardiac death, target vessel infarction and target lesion revascularisation, were observed in 98 patients (12-month incidence of 4.2% in the sCAD group, 6.4% in the ACS group; p=0.052). The 12-month incidence of definite scaffold thrombosis was 2.6% in ACS patients and 0.8% in XIENCE patients (p=0.006). In multivariate analysis, ACS was a predictor of DoCE (HR: 2.26 [1.34-3.81], p=0.002), PoCE (HR: 1.71 [1.13-2.58], p=0.011), and stent thrombosis (HR: 2.51 [1.13-5.60], p=0.025). In contrast, the incidence of target lesion revascularisation was not different between groups. There was no difference in the incidence of any of these endpoints among the different clinical presentations (unstable angina, non-ST-elevation infarction and ST-elevation infarction).

CONCLUSIONS

PoCE, DoCE and scaffold thromboses were more frequent in ACS patients, without any difference among different forms of ACS.

Long-term outcomes of bioresorbable vascular scaffold in ST-elevation myocardial infarction

BACKGROUND

Bioresorbable vascular scaffolds (BVS) implantation in selected patients with stable angina has been demonstrated feasible and safe. However, limited data are currently available on long-term outcomes after BVS implantation for ST-elevation myocardial infarction (STEMI). Therefore, we sought to assess the safety, efficacy and long-term results of BVS implantation in STEMI patients.

METHODS

Retrospective review of all STEMI patients treated with the Absorb^® BVS (Abbott Vascular, Santa Clara, CA) or conventional drug eluting stent (DES) between 1 April 2013 and 30 March 2014. Primary outcomes were procedural success, device thrombosis and device-oriented composite endpoint (DOCE) including cardiac death, target vessel myocardial infarction and target lesion revascularization. The study included 54 BVS patients and 121 DES patients.

RESULTS

Patients were slightly younger in the BVS group (60 vs. 63 years old, p = .03). Other baseline characteristics were comparable between the two groups. Procedural success was achieved in all patients. Median follow-up was 901 days and 849 days for BVS and DES patients, respectively (p = .01). The cumulative incidence of DOCE was not significantly different between the BVS and DES groups (7.5% vs. 9.1%, hazard ratio [HR]: 0.74 [95% confidence interval (CI): 0.26-2.2], p = NS). Rate of probable/definite device thrombosis were not statistically different between both groups (3.7% vs. 3.3%, p = NS).

CONCLUSIONS

The results of this single-centre retrospective study, one of the first assessing long-term safety and efficacy of BVS in STEMI, seems reassuring with similar long-term results as compared with patients treated with conventional DES.

Impact of calcium on procedural and clinical outcomes in lesions treated with bioresorbable vascular scaffolds - A prospective BRS registry study

BACKGROUND

There is limited data on the impact of calcium (Ca) on acute procedural and clinical outcomes in patients with lesions treated with bioresorbable vascular scaffolds (BRS). We sought to evaluate the effect of calcium on procedural and clinical outcomes in a 'real world' population.

METHODS

Clinical outcomes were compared between patients with at least 1 moderately or heavily calcified lesion (Ca) and patients with no/mild calcified lesions (non-Ca) enrolled in our institutional BRS registry.

RESULTS

455 patients (N) with 548 lesions (L) treated with 735 BRS were studied. Patients in the Ca group (N=160, L=200) had more complex (AHA B2/C lesion: 69.0% in Ca vs 14.9% in non-Ca, p<0.001) and significantly longer lesions (27.80±15.27 vs 19.48±9.92mm, p<0.001). Overall device success rate was 99.1% with no significant differences between the groups. Despite more aggressive lesion preparation and postdilation compared to non Ca, acute lumen gain was significantly less in Ca lesions (1.50±0.66 vs 1.62±0.69mm, p=0.040) with lower final MLD (2.28±0.41 vs 2.36±0.43, p=0.046). There were no significant differences in all-cause mortality, total definite scaffold thrombosis (ST), target lesion revascularization and myocardial infarction between the 2 groups. Late ST was more frequent in the Ca group compared to non Ca group (late ST: 2.1 vs 0%, p=0.02).

CONCLUSIONS

Clinical outcomes after BRS implantation in calcified and non-calcified lesions were similar. A remarkable difference in timing of thrombosis was observed, with an increased rate of late thrombosis in calcified lesions.

Thirty-Day and One-Year Clinical Outcomes of Bioresorbable Vascular Scaffold Implantation: A Single-Center Experience

Background

Available data on the use of the Bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, CA) in real-world patients is limited, particularly in Asian populations. The aim of this study was to assess clinical outcomes of patients treated with a BVS in real-world practice in Taiwan.

Methods

This study focused on 156 patients with coronary artery disease and a total of 249 lesions who received BVS implantation from October 2012 to October 2015. The study's primary endpoint was major adverse cardiac event (MACE), such as a myocardial infarction (MI), target vessel revascularization (TVR), target lesion revascularization (TLR), definite or possible scaffold thrombosis, cardiovascular death, and all-cause mortality during the thirty-day follow-up period. The secondary endpoint was MACE during the one-year follow-up period. Additionally, the composite clinical secondary endpoint was target lesion failure (TLF), which was called device-oriented composite endpoint.

Results

The average age of the patients was 60.34 ± 10.15 years, and 81.4% were male. The average of Syntax score was 12.42 ± 8.77 points. 44.2 % lesions were type B2 or C. At 31 days, one patient experienced a MACE (1/156) the composite of two TLF (2/249) with ST elevation MI, which was related to scaffold thrombosis. At one-year, 5.1 % (8/156) of the patients experienced a MACE and 3.6% (9/249) of the lesions experienced a TLF. There was no cardiovascular or all-cause mortality in the 30-day follow-up. The one-year cardiovascular and all-cause mortality rates were each 1.3%, respectively. Diabetes, ostial lesion, bifurcation lesion, and non-standard dual anti-platelet therapy (DAPT) were the strong associations of one-year TLF.

Conclusions

Even with difficult and complex lesions of patients in this study, acceptable outcomes were achieved with low definite or possible scaffold thrombosis rates after BVS implantation. And despite anatomical issues, it is important to complete standard DAPT.

Coronary Bioresorbable Vascular Scaffold Use in the Treatment of Coronary Artery Disease

Bioresorbable vascular scaffolds (BVS) represent a promising novel approach for the treatment of coronary artery disease. BVS promise to address some of the well-known limitations of current drug-eluting stents, while providing a transient scaffolding of the vessel to prevent acute vessel closure/recoil. Drug elution by BVS prevents neointimal proliferation in a similar fashion to drug-eluting stents, and complete bioresorption is associated with late vessel lumen enlargement, plaque regression, and restoration of vasomotion. Based on the pathophysiological reasons and on the results derived from clinical studies, BVS are increasingly being used in clinical practice. The aim of this review is to provide an overview of the current evidence supporting the use of BVS in clinical practice. In particular, we will discuss the randomized controlled trials and registries evaluating the clinical outcome of these devices, with a special focus on their application in patients with acute coronary syndrome and in specific lesion subsets (bifurcations, chronic total occlusions, and in-stent restenosis).

Possible mechanical causes of scaffold thrombosis: insights from case reports with intracoronary imaging

The advent of intracoronary stents has greatly increased the safety and applicability of percutaneous coronary interventions. One of the drawbacks of drug-eluting stents (DES) is the increased risk of late and very late stent thrombosis (ST). It was anticipated that the risks of ST after DES implantation would be solved with the advent of fully biodegradable scaffolds, which offer the possibility of transient scaffolding of the vessel to prevent acute vessel closure and recoil while also transiently eluting an antiproliferative drug to counteract constrictive remodelling and excessive neointimal hyperplasia. In spite of the enthusiasm for the concept of bioresorbable scaffolds, current clinical data on the Absorb bioresorbable vascular scaffold (BVS) have generated concerns about scaffold thrombosis (ScT) in both the early and late phases. However, the causes of ScT in both the early and late phases have yet to be fully elucidated. This article seeks to provide insights into the possible mechanical causes of ScT in the early and late phases with data stemming from intracoronary imaging (intravascular ultrasound and optical coherence tomography) of the currently published ScT cases following the implantation of BVS and reviews the practical recommendations for implantation of the BVS made by a group of experts.

Bioresorbable Vascular Scaffold Korean Expert Panel Report

Bioresorbable vascular scaffold (BRS) is an innovative device that provides structural support and drug release to prevent early recoil or restenosis, and then degrades into nontoxic compounds to avoid late complications related with metallic drug-eluting stents (DESs). BRS has several putative advantages. However, recent randomized trials and registry studies raised clinical concerns about the safety and efficacy of first generation BRS. In addition, the general guidance for the optimal practice with BRS has not been suggested due to limited long-term clinical data in Korea. To address the safety and efficacy of BRS, we reviewed the clinical evidence of BRS implantation, and suggested the appropriate criteria for patient and lesion selection, scaffold implantation technique, and management.

Arterial healing following primary PCI using the Absorb everolimus-eluting bioresorbable vascular scaffold (Absorb BVS) versus the durable polymer everolimus-eluting metallic stent (XIENCE) in patients with acute ST-elevation myocardial infarction: rationale and design of the randomised TROFI II study

AIMS

The Absorb bioresorbable vascular scaffold (Absorb BVS) provides similar clinical outcomes compared with a durable polymer-based everolimus-eluting metallic stent (EES) in stable coronary artery disease patients. ST-elevation myocardial infarction (STEMI) lesions have been associated with delayed arterial healing and impaired stent-related outcomes. The purpose of the present study is to compare directly the arterial healing response, angiographic efficacy and clinical outcomes between the Absorb BVS and metallic EES.

METHODS AND RESULTS

A total of 191 patients with acute STEMI were randomly allocated to treatment with the Absorb BVS or a metallic EES 1:1. The primary endpoint is the neointimal healing (NIH) score, which is calculated based on a score taking into consideration the presence of uncovered and malapposed stent struts, intraluminal filling defects and excessive neointimal proliferation, as detected by optical frequency domain imaging (OFDI) six months after the index procedure. The study will provide 90% power to show non-inferiority of the Absorb BVS compared with the EES.

CONCLUSIONS

This will be the first randomised study investigating the arterial healing response following implantation of the Absorb BVS compared with the EES. The healing response assessed by a novel NIH score in conjunction with results on angiographic efficacy parameters and device-oriented events will elucidate disease-specific applications of bioresorbable scaffolds.

Magmaris preliminary recommendation upon commercial launch: a consensus from the expert panel on 14 April 2016

Bioresorbable scaffolds represent an exciting milestone in the development of coronary stent technology with the potential to substantially improve the management of patients with coronary artery disease. In an attempt to provide first recommendations for the technology, experienced experts involved in the first-in-man studies met in Zurich on the 14 April 2016 in order to reach consensus on a responsible market introduction. This document will be updated regularly as new information from clinical trials becomes available and should be understood as a review of current data, opportunities, expectations, advice, and recommendations for future investigations.

Are acute coronary syndromes an ideal scenario for bioresorbable vascular scaffold implantation?

Bioresorbable vascular scaffolds (BRS) represent the latest innovation in the field of interventional cardiology. BRS have recently been introduced in routine clinical practice and their use has progressively extended in everyday clinical practice. The BRS use appears theoretically attractive in patients presenting with acute coronary syndromes (ACS) as they are generally young with long life expectancy, thus possibly benefiting more of the so-called vascular reparative therapy. Furthermore, "culprit" lesions are usually softer and more easily expandable by current BRS compared to stable chronic lesions. However an increased risk of BRS thrombosis has been reported in clinical trials excluding ACS patients. Therefore, concerns have been raised on the safety of BRS implantation in the ACS setting in which the risk of thrombotic recurrences is definitely higher (compared to stable lesions) independently by the device implanted. Aim of this review is to provide an overview of the available data on the BRS performance in ACS patients.

Conformability in everolimus-eluting bioresorbable scaffolds compared with metal platform coronary stents in long lesions

The aim of this study was to determine if there are significant differences in curvature of the treated vessel after the deployment of a polymeric BRS or MPS in long lesions. The impact of long polymeric bioresorbable scaffolds (BRS) compared with metallic platform stents (MPS) on vessel curvature is unknown. This retrospective study compares 32 patients who received a single everolimus-eluting BRS with 32 patients treated with a single MPS of 28 mm. Quantitative coronary angiography (QCA) was used to evaluate curvature of the treatment and peri-treatment region before and after percutaneous coronary intervention (PCI). Baseline demographic and angiographic characteristics were similar between the BRS and MPS groups. Pretreatment lesion length was 22.19 versus 20.38 mm in the BRS and MPS groups respectively (p = 0.803). After treatment, there was a decrease in median diastolic curvature in the MPS group (from 0.257 to 0.199 cm^-1, p = 0.001). A similar trend was observed in the BRS group but did not reach statistical significance (median diastolic curvature from 0.305 to 0.283 cm^-1, p = 0.056). Median Percentage relative change in diastolic curvature was lower in the BRS group compared with the MPS group (BRS vs. MPS: 7.48 vs. 29.4%, p = 0.013). By univariate analysis, use of MPS was an independent predictor of change in diastolic curvature (p = 0.022). In the deployment of long coronary scaffolds/stents (28 mm in length), BRS provides better conformability compared with MPS.

Everolimus-eluting bioresorbable vascular scaffolds for treatment of complex chronic total occlusions

AIMS

Bioresorbable vascular scaffolds (BVS) represent a novel therapeutic option for the treatment of coronary artery diseases. The objective of this study was to evaluate the feasibility of BVS implantation in complex chronic total occlusions (CTO).

METHODS AND RESULTS

The present report is a multicentre registry evaluating results after BVS deployment in challenging CTO lesions, defined as J-CTO score ≥2 (difficult or very difficult). A total of 105 patients were included in the present analysis. The mean J-CTO score was 2.61 (difficult 52.4%, very difficult 47.6%). Device success and procedural success rates were 98.1% and 97.1%, respectively. The retrograde approach was used in 25.7% of cases. After wire crossing, predilatation was performed in all cases with a mean predilatation balloon diameter of 2.73±0.43 mm. The mean scaffold length was 59.75±25.85 mm, with post-dilatation performed in 89.5% of the cases and a mean post-dilatation balloon diameter of 3.35±0.44 mm. Post-PCI minimal lumen diameter was 2.50±0.51 mm and percentage diameter stenosis 14.53±10.31%. At six-month follow-up, a total of three events were reported: one periprocedural myocardial infarction, one late scaffold thrombosis and one additional target lesion revascularisation.

CONCLUSIONS

The present report suggests the feasibility of BVS implantation in complex CTO lesions, given adequate lesion preparation and post-dilatation, with good acute angiographic results and midterm clinical outcomes.

Initial experience with everolimus-eluting bioresorbable vascular scaffolds for treatment of patients presenting with acute myocardial infarction: a propensity-matched comparison to metallic drug eluting stents 18-month follow-up of the BVS STEMI first study

AIMS

Limited data are currently available on midterm outcomes after implantation of everolimus-eluting bioresorbable vascular scaffolds (BVS) for treatment of acute ST-elevation myocardial infarction (STEMI).

METHODS AND RESULTS

Patients presenting with STEMI and undergoing primary percutaneous coronary intervention in the initial experience with BVS were evaluated and compared with patients treated with everolimus-eluting metal stents (EES) by applying propensity matching. Quantitative coronary angiography analysis, and 18-month clinical follow-up were reported. A total of 302 patients were analysed, 151 with BVS and 151 with EES. Baseline clinical characteristics were similar between groups. Final TIMI 3 flow was 87.4% vs. 86.1%, p=0.296. At 18-month follow-up, all-cause mortality was 2.8% vs. 3.0% in the BVS and EES groups respectively, p=0.99; the MACE rate was higher in the BVS group (9.8% vs. 3.6%, p=0.02); target lesion revascularisation was 5.7% vs. 1.3%, p=0.05. The 30-day MACE rate in BVS patients without post-dilatation was 6.8%, while in patients with post-dilatation it was 3.6%. Scaffold thrombosis (ST) occurred primarily in the acute phase (acute ST 2.1% vs. 0.7%, p=0.29; subacute 0.7% vs. 0.7%, p=0.99; late 0.0% vs. 0.0%; very late 1.5% vs. 0.0%, p=0.18). All three BVS cases with acute ST had no post-dilatation at the index procedure.

CONCLUSIONS

STEMI patients treated during the early experience with BVS had similar acute angiographic results as compared with the EES group. Clinical midterm follow-up data showed a higher clinical events rate compared with metal stents. The majority of clinical events occurred in the early phase after implantation and mainly in cases without post-dilatation. Optimisation of the implantation technique in the acute clinical setting is of paramount importance for optimal short and mid-term outcomes.

Long-term follow-up after bioresorbable vascular scaffold implantation in STEMI patients: PRAGUE-19 study update

AIMS

Early clinical results after implantation of bioresorbable vascular scaffolds (BVS) in ST-elevation myocardial infarction (STEMI) are encouraging, but long-term data are missing. This study evaluates long-term outcome in STEMI patients with implanted BVS.

METHODS AND RESULTS

The PRAGUE-19 study is an academic study enrolling consecutive STEMI patients with the intention to implant BVS. A total of 580 STEMI patients were screened between December 2012 and March 2015; 117 patients fulfilled entry criteria and BVS was successfully implanted in 114 (97%) of them. The primary combined clinical endpoint (death, reinfarction or target vessel revascularisation) occurred in 11.5% during the mean follow-up period of 730±275 days with overall mortality of 4.4%. Definite scaffold thrombosis occurred in two patients in the early phase after BVS implantation; there was no late thrombosis. Quantitative coronary angiography (10 patients) at three years demonstrated late lumen loss of 0.2±0.33 mm and optical coherence tomography showed minimal lumen area of 5.3±1.37 mm2 and neointimal hyperplasia area of 2.9±0.48 mm2. BVS struts were still visible at three years and 99.4% of them were well apposed and covered.

CONCLUSIONS

Encouraging clinical and imaging results after BVS implantation in STEMI patients persist during long-term follow-up.

Contemporary management of ST-segment elevation myocardial infarction

ST-elevation myocardial infarction (STEMI), which constitutes nearly 25-40 % of current acute myocardial infarction (AMI) cases, is a medical emergency that requires prompt recognition and treatment. Since the 2013 STEMI practice guidelines, a wealth of additional data that may further advance optimal STEMI practices has emerged. These data highlight the importance of improving patient treatment and transport algorithms for STEMI from non-primary percutaneous coronary intervention (PCI) centers. In addition, a focus on the reduction of total pain-to-balloon (P2B) times rather than simply door-to-balloon (D2B) times may further improve outcomes after primary PCI for STEMI. The early administration of newer oral P2Y12 inhibitors, including crushed forms of these agents for faster absorption, represents another treatment advancement. Recent data also suggest avoiding concurrent morphine use due to interactions with P2Y12 inhibitors. Furthermore, new technological advancements and investigational therapies, including Bioresorbable Vascular Scaffolds and the use of pre-intervention intravenous microbubbles with transthoracic ultrasound, hold promise to play a useful role in future STEMI care. Despite these advancements, the prompt recognition of STEMI, at both the patient and health care system level, remains the cornerstone of optimal treatment.

A prospective evaluation of a standardized strategy for the use of a polymeric everolimus-eluting bioresorbable scaffold in ST-segment elevation myocardial infarction: Rationale and design of the BVS STEMI STRATEGY-IT study

OBJECTIVES

To assess the feasibility and the clinical results following a prespecified bioresorbable vascular scaffold (Absorb BVS) implantation strategy in ST-elevation myocardial infarction (STEMI) patients.

BACKGROUNDS

Concerns raised about the BVS safety in STEMI setting because a not negligible thrombosis rate was reported within 30 days and 12 months after implantation. Technical procedural issues related to the structural BVS features were advocated as probable causes for the thrombotic events.

METHODS

This is an investigators-owned and -directed, prospective, nonrandomized, single-arm multicenter registry intended to obtain data from 500 consecutive STEMI patients undergoing primary PCI with BVS (1.1 or GT1) following a prespecified implantation protocol. The study is recorded in ClinicalTrials.gov with the identifier: NCT02601781.

RESULTS

The primary endpoint is a device-oriented composite end-point (DOCE) of cardiac death, any myocardial infarction clearly attributable to the intervention culprit vessel and ischemic-driven target lesion revascularization within 30 days after the index procedure. The DOCE will be assessed even at 6-month, 1-, 3-, and 5-year follow-up.

CONCLUSIONS

This will be the first study investigating the feasibility and the early- and long-term clinical impact of a prespecified BVS implantation protocol in thrombotic lesions causing STEMI. Here, we describe the rationale and the design of the study. © 2016 Wiley Periodicals, Inc.

Scaffold Thrombosis After Percutaneous Coronary Intervention With ABSORB Bioresorbable Vascular Scaffold: A Systematic Review and Meta-Analysis

OBJECTIVES

The aim of this study was to determine the risk of scaffold thrombosis (ST) after percutaneous coronary intervention (PCI) with placement of an ABSORB bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, California) by conducting a systematic review and meta-analysis.

BACKGROUND

PCI with BVS placement holds great potential, but concern has recently been raised regarding the risk of ST.

METHODS

MEDLINE/PubMed, Cochrane CENTRAL, and meeting abstracts were searched for all studies that included outcomes data for patients after PCI with BVS placement. For studies comparing BVSs with drug-eluting stents (DES), pooled estimates of outcomes, presented as odds ratios (ORs) with 95% confidence intervals (CIs), were generated with random-effects models.

RESULTS

Our analysis included 10,510 patients (8,351 with a BVS and 2,159 with DES) with a follow-up of 6.4 ± 5.1 months and 60 ± 11 years of age; 78% were male, 36% had stable angina, and 59% had acute coronary syndrome (ACS). Among patients with a BVS, cardiovascular death occurred in 0.6%, myocardial infarction (MI) in 2.1%, target lesion revascularization in 2.0%, and definite/probable ST in 1.2% of patients. Of BVS patients, 0.27% had acute ST and 0.57% had subacute ST. Meta-analysis demonstrated that patients who received a BVS were at a higher risk of MI (OR: 2.06, 95% CI: 1.31 to 3.22, p = 0.002) and definite/probable ST (OR: 2.06, 95% CI: 1.07 to 3.98, p = 0.03) compared with patients who received DES, whereas there was a trend toward decreased all-cause mortality with a BVS (OR: 0.40, 95% CI: 0.15 to 1.06, p = 0.06).

CONCLUSIONS

Patients undergoing PCI with a BVS had increased definite/probable ST and MI during follow-up compared with DES. Further studies with long-term follow-up are needed to assess the risk of ST with a BVS.

Bioresorbable vascular scaffolds - basic concepts and clinical outcome

The introduction of percutaneous treatment of coronary artery stenosis with balloon angioplasty was the first revolution in interventional cardiology; the advent of metallic coronary stents (bare and drug-eluting) marked the second and third revolutions. However, the latest generation of drug-eluting stents is limited by several factors. Permanent vessel caging impairs arterial physiology, and the incidence of very late stent thrombosis - although lower with the second generation than with the first generation of drug-eluting stents - remains a major concern. This complication is mainly related to the presence of permanent metallic implants, chronic degeneration triggered by an inflammatory response to the coating polymer, and/or adverse effects of antiproliferative drugs on endothelial regeneration. In 2011, self-degrading coronary stents - the bioresorbable vascular scaffolds (BVS) - were introduced into clinical practice, showing good short-term results owing to their adequate strength. The advantage of these devices is the transient nature of vascular scaffolding, which avoids permanent vessel caging. In this Review, we summarize the latest research on BVS, with a particular emphasis on the implantation technique (which is different from that used with metallic stents) to outline the concept that BVS deployment methods have a major effect on procedural success and prognosis of patients with coronary artery stenosis. Furthermore, the clinical outcome of BVS in randomized clinical trials and in phase IV studies are discussed in different pathophysiological settings, such as stable or acute coronary disease. Finally, all the available data on the safety profile of BVS regarding scaffold thrombosis are discussed.

Bioresorbable scaffolds in daily clinical routine: a practical review of all-comers results

PURPOSE OF REVIEW

Bioresorbable scaffolds (BRS) are a major advancement in interventional cardiology, but experience with BRS use in daily routine is currently limited. Here, we review technical features of commercially available BRS and place them in context with current clinical scientific evidence.

RECENT FINDINGS

Everolimus and novolimus-eluting poly-L-lactic acid (PLLA)-based BRS are commercially available in Europe. The everolimus-eluting BRS is the most widely investigated BRS and several all-comers investigations with this device are ongoing. Of the patients in these studies, 37-100% underwent catheterization due to acute coronary syndrome and up to 25% were diabetic. Up to 64.7% of all lesions treated were considered to be complex. Follow-up varied between 30 days and 1 year. The target lesion revascularization rate was up to 10% and scaffold thrombosis was 0-3%.

SUMMARY

Accumulating data on BRS application are now available. Several studies have demonstrated that BRS implantation is technically feasible in a variety of different patient subsets and clinical presentations, and follow-up results support BRS use. Patients with acute coronary syndrome represent the most investigated subpopulation, and results suggest that BRS use for this indication is reasonable.

Bioresorbable vascular scaffolds technology: current use and future developments

Coronary bioresorbable vascular scaffolds are a new appealing therapeutic option in interventional cardiology. The most used and studied is currently the Absorb BVS™. Its backbone is made of poly-L-lactide and coated by a thin layer of poly-D,L-lactide, it releases everolimus and is fully degraded to H2O and CO2 in 2-3 years. Absorb BVS™ seems to offer several theoretical advantages over metallic stent, as it gives temporary mechanical support to vessel wall without permanently caging it. Therefore, long-term endothelial function and structure are not affected. A possible future surgical revascularization is not compromised. Natural vasomotion in response to external stimuli is also recovered. Several observational and randomized trials have been published about BVS clinical outcomes. The main aim of this review is to carry out a systematic analysis about Absorb BVS™ studies, evaluating also the technical improvements of the Absorb GT1 BVS™.

Optimisation of percutaneous coronary intervention: indispensables for bioresorbable scaffolds

INTRODUCTION

With new developments in percutaneous coronary intervention (PCI), such as the introduction of bioresorbable scaffolds (BRS), percutaneous treatment of coronary artery diseases has entered a new era. Without metallic remnants, BRSs appear able to overcome several limitations of the existing metallic stents and provide a physiologic treatment of coronary artery pathology.

AREAS COVERED

BRS have different mechanical properties compared to the traditional metallic stents that should be taken into account during their implantation. Lesion selection, device sizing and satisfied pre-dilatation should be implemented prudently. Although intravascular imaging is not mandatory for the implantation of BRSs it may have a value in optimizing device deployment assess final results and reduce the risk of device related adverse events such as re-stenosis, or scaffold thrombosis. This review aims to reveal the crucial points about the methods of optimization in each steps of BRS implantation. Expert commentary: The target lesions for BRS should be selected meticulously. Pre-dilatation, post-dilatation and intra-vascular imaging techniques should be implemented appropriately to avoid undesirable events after scaffold implantation.

Everolimus-eluting bioresorbable vascular scaffolds implanted in coronary bifurcation lesions: Impact of polymeric wide struts on side-branch impairment

BACKGROUND

Limited data are available on bioresorbable vascular scaffolds (BVS) performance in bifurcations lesions and on the impact of BVS wider struts on side-branch impairment.

METHODS

Patients with at least one coronary bifurcation lesion involving a side-branch ≥2mm in diameter and treated with at least one BVS were examined. Procedural and angiographic data were collected and a dedicated methodology for off-line quantitative coronary angiography (QCA) in bifurcation was applied (eleven-segment model), to assess side-branch impairment occurring any time during the procedure. Two- and three-dimensional QCA were used. Optical coherence tomography (OCT) analysis was performed in a subgroup of patients and long-term clinical outcomes reported.

RESULTS

A total of 102 patients with 107 lesions, were evaluated. Device- and procedural-successes were 99.1% and 94.3%, respectively. Side-branch impairment occurring any time during the procedure was reported in 13 bifurcations (12.1%) and at the end of the procedure in 6.5%. Side-branch minimal lumen diameter (Pre: 1.45±0.41mm vs Final: 1.48±0.42mm, p=0.587) %diameter-stenosis (Pre: 26.93±16.89% vs Final: 27.80±15.57%, p=0.904) and minimal lumen area (Pre: 1.97±0.89mm(2) vs Final: 2.17±1.09mm(2), p=0.334), were not significantly affected by BVS implantation. Mean malapposed struts at the bifurcation polygon-of-confluence were 0.63±1.11.

CONCLUSIONS

The results of the present investigation suggest feasibility and relative safety of BVS implantation in coronary bifurcations. BVS wide struts have a low impact on side-branch impairment when considering bifurcations with side-branch diameter≥2mm.

Differential thrombotic prolapse burden in either bioresorbable vascular scaffolds or metallic stents implanted during acute myocardial infarction: The snowshoe effect: Insights from the maximal footprint analysis

BACKGROUND

The hypothesized increased thrombus entrapment during bioresorbable vascular scaffold implantation in acute myocardial infarction, the so-called "snowshoe effect" has never been demonstrated.

METHODS

Patients enrolled in the BVS STEMI FIRST study matched with STEMI patients implanted with everolimus-eluting metal stents (EES) and undergoing optical coherence tomography (OCT) at the index procedure were compared. Quantitative coronary angiography analysis and optical coherence tomography data for evaluation of thrombotic prolapse were reported. Percentage maximal footprint (%MFP) analysis as an indicator of the snowshoe effect was performed.

RESULTS

A total of 302 patients were analyzed (151 with BVS and 151 with EES). Of those patients 30 implanted with BVS and 17 implanted with EES were imaged at the index procedure with OCT. Baseline clinical characteristics, TIMI-flow and thrombus burden were similar between groups. Aspiration thrombectomy was similarly performed in the two groups (BVS 83.3% vs 94.1% EES, p=0.405). At the end of the procedure, final TIMI 3 flow was achieved in 93.3% and 82.4% of BVS and EES patients respectively (p=0.296). The %MFP was significantly higher in the BVS treated patients (36.59±5.65% vs 17.61±4.30, p<0.001). The results of the OCT analysis showed a mean prolapse area (0.61±0.26mm(2) vs 0.90±0.31mm(2), p=0.001) and a percentage prolapse area (7.11±2.98mm(2) vs 9.98±2.90mm(2), p=0.002) significantly higher in the EES group.

CONCLUSIONS

Scaffold structural characteristics such as strut width may play a role in terms of thrombus dislodgment patterns and acute prolapsing material.

Bioresorbable vascular scaffolds-time to vanish?

The fully bioabsorbable vascular scaffold (BVS) has been developed to reduce late adverse events after coronary stenting such as device thrombosis. The device consists of polylactic acid, which is gradually absorbed within the first few years after its implantation. The initial experience with the device in low-risk patients presenting with simple lesions was satisfying and generated optimism among interventional cardiologists by promising better patient outcomes. However, the unrestricted use of the device in patients presenting with a higher baseline risk and more complex lesions came at the cost of alarmingly high rates of early device thrombosis. The performance of the device largely depends on an optimal implantation technique, which differs from that employed with metallic drug-eluting stents due to the device's distinct physical propensity. Mid-term outcomes in large-scale randomized clinical trial were disappointing. Although its non-inferiority compared to metallic everolimus-eluting stents was formally met, there was a clear trend towards an increased occurrence of myocardial infarction and device thrombosis during the first year after device implantation. However, the BVS's putative advantages are expected to manifest themselves at long-term, that is 3 to 5 years after the device has been implanted. Evidence pertaining to these long-term outcomes is eagerly awaited.

Bioresorbable vascular scaffolds in patients with acute myocardial infarction: a new step forward to optimized reperfusion?

Bioresorbable vascular scaffolds (BVS) represent a disruptive technology that has caused a new revolution in interventional cardiology. BVS appear to be particularly appealing in patients presenting with an acute myocardial infarction (MI). The available evidence on the value of BVS implantation in this challenging scenario is very promising but still limited. Results come from preliminary small observational studies, prospective registries that include a control group, and from scarce randomized clinical trials with surrogate mechanistic or angiographic primary end-points. Further studies, powered for clinical endpoints, are required to establish the relative safety and efficacy of BVS vs. new-generation metallic drug-eluting stents (DES) in patients with ST-segment elevation acute MI.

Current and novel approaches to treat patients presenting with ST elevation myocardial infarction

INTRODUCTION

Primary percutaneous coronary intervention (PCI) represents the gold-standard treatment for patients presenting with an ST-elevation myocardial infarction (STEMI). Acute myocardial infarction is a complex clinical scenario, and an appropriate therapeutic approach could be represented by a balanced integration between healthcare system and medical competence.

AREAS COVERED

In this review we discuss how a primary PCI network, and the new therapeutic options could be coupled in order to obtain improved clinical outcomes. The present report will focus on three main issues related to STEMI patients, namely, out of hospital management, primary PCI and pharmacological treatment. Expert commentary: A possible correct approach to a patient presenting a STEMI could be considered as a stepwise process, given by 5 steps: reducing the time to reperfusion; dual antiplatelet administration; radial access; new generation drug eluting stent implantation; long term management.

Absorb bioresorbable stents for the treatment of coronary artery disease

Bioresorbable stents are considered to be the 'fourth revolution' in percutaneous coronary intervention. The first clinically available Absorb(®) bioresorbable device is made of poly-l-lactic acid polymer and elutes everolimus. The process of bioresorption is completed in 3 years. The introduction of this device into clinical practice went through several logical phases: first-in-man studies, randomized Absorb II study with moderately complex patients and lesions, registries of real life patient population and reports of challenging cases. The procedural results are excellent; many insights have been gained by intracoronary imaging. Intermediate-term outcomes are very encouraging both from imaging and from clinical perspectives. The issue of increased stent thrombosis rate was raised in one study, but other studies have been reassuring. Excellent lesion preparation, sizing and complete expansion of the Absorb device are crucial for optimal procedural and clinical results. Results of ongoing large randomized studies will determine the future role of this technology.

Are BVS suitable for ACS patients? Support from a large single center real live registry

OBJECTIVES

To investigate one-year outcomes after implantation of a bioresorbable vascular scaffold (BVS) in patients presenting with acute coronary syndrome (ACS) compared to stable angina patients.

BACKGROUND

Robust data on the outcome of BVS in the setting of ACS is still scarce.

METHODS

Two investigator initiated, single-center, single-arm BVS registries have been pooled for the purpose of this study, namely the BVS Expand and BVS STEMI registries.

RESULTS

From September 2012-October 2014, 351 patients with a total of 428 lesions were enrolled. 255 (72.6%) were ACS patients and 99 (27.4%) presented with stable angina/silent ischemia. Mean number of scaffold/patient was 1.55±0.91 in ACS group versus 1.91±1.11 in non-ACS group (P=0.11). Pre- and post-dilatation were performed less frequent in ACS patients, 75.7% and 41.3% versus 89.0% and 62.0% respectively (P=0.05 and P=0.001). Interestingly, post-procedural acute lumen gain and percentage diameter stenosis were superior in ACS patients, 1.62±0.65mm (versus 1.22±0.49mm, P<0.001) and 15.51±8.47% (versus 18.46±9.54%, P=0.04). Major adverse cardiac events (MACE) rate at 12months was 5.5% in the ACS group (versus 5.3% in stable group, P=0.90). One-year definite scaffold thrombosis rate was comparable: 2.0% for ACS population versus 2.1% for stable population (P=0.94), however, early scaffold thromboses occurred only in ACS patients.

CONCLUSIONS

One-year clinical outcomes in ACS patients treated with BVS were similar to non-ACS patients. Acute angiographic outcomes were better in ACS than in non-ACS, yet the early thrombotic events require attention and further research.

Bioresorbable scaffold - A magic bullet for the treatment of coronary artery disease?

Today, drug-eluting metal stents are considered the gold standard for interventional treatment of coronary artery disease. While providing inhibition of neointimal hyperplasia, drug-eluting metal stents have many limitations such as the risk of late and very late stent thrombosis, restriction of vascular vasomotion and chronic local inflammatory reaction due to permanent implantation of a 'metallic cage', recognized as a foreign body. Bioresorbable scaffold stents (BRS) are a new solution, which is trying to overcome the limitation of the 'metallic cage'. This structure provides short-term scaffolding of the vessel and then disappears, leaving nothing behind. The purpose of this review is to present the theoretical rationale for the use of BRS and to outline the clinical outcomes associated with their use in terms of data obtained from RCTs, clinical trials, registries and real life use. We have also tried to answer all questions on this intervention based on available data, with a focus on ABSORB BVS (Abbott Vascular, Santa Clara, USA). We consider that this new technology can be the "magic bullet" to treat coronary artery disease.

Clinical, Angiographic, Functional, and Imaging Outcomes 12 Months After Implantation of Drug-Eluting Bioresorbable Vascular Scaffolds in Acute Coronary Syndromes

OBJECTIVES

The purpose of this study was to describe the multimodal outcome 12 months after implantation of coronary bioresorbable scaffolds (BVS) for the treatment of patients with acute coronary syndromes (ACS).

BACKGROUND

Functional and imaging data on the use of BVS are limited to simple, stable lesions; in the setting of ACS, only short-term clinical follow-up data are available, and no information from intracoronary imaging and vasomotion tests has been reported.

METHODS

A total of 133 patients (age 62 ± 12 years, 74% males, 15% diabetic) underwent BVS (n = 166) implantation for the treatment of thrombotic lesions in the setting of ACS (43% non-ST-segment elevation myocardial infarction, 38% ST-segment elevation myocardial infarction, 20% unstable angina). Clinical, angiographic, intracoronary imaging, and vasomotor endpoints were evaluated at 12 months.

RESULTS

During the 374 days (interquartile range: 359 to 411 days) of follow-up, there were 4 deaths; 3 definite and 1 probable in-BVS thromboses (all in the first 6 months). At 12-month angiography (75 patients, 83 BVS), in-segment late lumen loss was 0.19 ± 0.45 mm, and 3 (4%) patients showed binary restenosis. Optical coherence tomography (80 BVS, n = 70) showed a mean lumen area of 6.3 ± 2.3 mm(2). Malapposition was evidenced in 21 (26%) BVS. Endothelium-dependent and -independent vasodilation were observed in 48% and 49% of the BVS.

CONCLUSIONS

Twelve months after BVS implantation, clinical, intracoronary imaging, and vasomotion data appear to provide a rationale for the use of BVS in the setting of ACS and the basis for a randomized study.

Angiographic and optical coherence tomography insights into bioresorbable scaffold thrombosis: single-center experience

BACKGROUND

As bioresorbable vascular scaffolds (BVSs) are being increasingly used in complex real-world lesions and populations, BVS thrombosis cases have been reported. We present angiographic and optical coherence tomography (OCT) findings in a series of patients treated in our center for definite bioresorbable scaffold thrombosis.

METHODS AND RESULTS

Up to June 2014, 14 patients presented with definite BVS thrombosis in our center. OCT was performed in 9 patients at the operator's discretion. Angiographic and OCT findings were compared with a control group comprising 15 patients with definite metallic stent thrombosis. In the BVS group, time interval from index procedure to scaffold thrombosis ranged from 0 to 675 days. Incomplete lesion coverage by angiography was identified in 4 of 14 cases, malapposition by OCT in 5 of 9 cases, strut discontinuity in 2 of 9 cases, and underexpansion in 2 of 9 cases. Five patients had discontinued dual antiplatelet therapy, and in 3 of them discontinued dual antiplatelet therapy discontinuation had occurred the week preceding the event. There were no significant differences in angiographic or OCT findings between BVS and metallic stent thrombosis.

CONCLUSIONS

Suboptimal implantation with incomplete lesion coverage, underexpansion, and malapposition comprises the main pathomechanism for both early and late BVS thrombosis, similar to metallic stent thrombosis. Dual antiplatelet therapy discontinuation seems to also be a secondary contributor in several late events. Our observations suggest that several potential triggers for BVS thrombosis could be avoided.